A gene is edited inside a person's body to stop an age-related disease
Most gene editing so far has been done on cells taken out of the body and put back. Editing a gene inside a living person is the step that would let the damage of ageing be repaired where it sits. In 2021 a London group gave six people a single infusion of a CRISPR gene editor (a tool that cuts DNA at a chosen spot) packaged in fat droplets, which went to the liver and switched off the gene for transthyretin, a protein that misfolds and clogs the heart and nerves in an inherited disease and, in its ordinary form, in many old people. The protein fell by about nine tenths and stayed down. The treatment is in a large late-stage trial for the heart form of the disease, which was paused in late 2025 after a patient's liver was harmed, and restarted in March 2026 with closer liver monitoring; nothing is approved yet. That patient, a man in his eighties, died on 2025-11-05. Early trade reports linked the death to the liver event; the company's chief executive said in January 2026 that it followed an infection after a bowel perforation and was not caused by liver failure. The cause is not yet confirmed in a written company statement.
What would count
A person is given a treatment that edits a gene inside their body, and afterwards the gene's product is measurably changed in the way intended, in a peer-reviewed report. For the clinic rung: a regulator approves a gene-editing treatment given inside the body for an age-related disease, or for a disease of DNA damage, so a doctor can give it outside a trial.
Who settles it: The peer-reviewed trial report; the trial registry; the regulator's approval record for the clinic rung.
Where it stands
First human. Reached 26 June 2021, on the record of doi.org. Next rung within 1 to 5 years.
When it reaches the clinic: the project's estimate
This is the one thing on this page that is a judgment rather than a record. The project's estimate of the year it reaches the clinic is 2030, no earlier than 2028 and no later than 2042; the model draws from that range every run, with the likely year the most probable draw. Set 16 October 2026, a first pass awaiting an outside review.
| Rung | No earlier than | Most likely | No later than | |
|---|---|---|---|---|
| In clinical use | 2028 | 2030 | 2042 | feeds the year at the top |
| In wide use | 2032 | 2038 | 2060 |
Why. The late-stage heart trial was designed to read out around 2027 to 2028 before the hold; the likely year assumes the hold is resolved, the trial finishes a year or two late, and the first approval of an in-body gene editor for an age-related disease comes in 2030. The earliest assumes the nerve-disease trial, which is running, supports an approval first. The latest allows for the liver-safety problem ending this programme and a competitor taking most of a decade more.
Changes to this record
- 17 October 2026, description: patient's liver was harmed, and restarted in March 2026 with closer liver monitoring; nothing is approved yet. became patient's liver was harmed, and restarted in March 2026 with closer liver monitoring; nothing is approved yet. That patient, a man in his eighties, died on 2025-11-05. Early trade reports linked the death to the liver event; the company's chief executive said in January 2026 that it followed an infection after a bowel perforation and was not caused by liver failure. The cause is not yet confirmed in a written company statement.. [reading 2026-10-17] Adds the death in the heart trial and the two accounts of its cause, which the description of 2026-10-16 left out. The company's release of 2026-03-02 (intellia-2026) confirms the stop of 2025-10-29 and the restart; the death and its cause come from trade reports of the company's own remarks. The stage does not change. Source: Inc., 2 March 2026.
The last readings
- 17 October 2026 Left for the author
Nothing in the window 2026-10-10 to 2026-10-17 bears on the test, and the leaf's account of the pause and restart holds up: the regulator stopped both late-stage trials of the gene editor (nexiguran ziclumeran) on 2025-10-29 after one patient's liver enzymes and bilirubin rose sharply, lifted the stop on the nerve-disease trial on 2026-01-27, and lifted the stop on the heart trial in early March 2026 with closer liver monitoring, short-course steroid guidance and new exclusions, which trade coverage dated 2026-03-03 reports. The one thing the leaf does not mention, and the reason this is flagged rather than quiet, is that two trade reports say a patient in the heart trial died, with the company's chief executive saying in January 2026 that the investigation put the death down to infection and not to the liver event. The newest results seen are a 36-month follow-up of the small first trial presented at a heart-failure conference in 2026 from data cut on 2025-08-23, which is a conference presentation and a company slide deck, not the peer-reviewed report the settler names, and no 2026 peer-reviewed paper was found. Left for the author, resolved on 17 October 2026: The change I would make is to the leaf's description, which says only that the trial was paused after a patient's liver was harmed: I would add that a patient in the same heart trial died, and that the sponsor said in January 2026 that the death was from infection and not from the liver injury. It is not mine to make for two reasons. The reports are press only, one of them a trade news piece whose own text looked muddled, and the primary sources that would settle it (the sponsor's own release and the trial registry record) could not be opened from this session, so the fact is unchecked. It also changes a stage record's description, which the author writes. If it stands up, it belongs in the description or the verify list, not in the stage, because it does not touch the test.source 1, source 2, source 3, source 4
What the story so far says about it
On the record
- 2 March 2026Intellia Therapeutics Announces FDA Lift of Clinical Hold on MAGNITUDE Phase 3 Clinical Trial in ATTR-CM
Notes
Transthyretin amyloidosis in its non-inherited form is a disease of old age, which is why a treatment aimed at an inherited disease sits on this tree. The other way to the same end, a drug that steadies the protein without touching the gene, is approved and has its own leaf on the broken-proteins branch. This leaf does not ask for the editing to repair ageing damage in general; it asks for the tool to be in the clinic, because every DNA-repair leaf above it needs the tool first.
Not yet verified
These facts in the record were written from memory or from a secondary source and have not yet been checked against the paper, the regulator's record or the registry. Nothing here is presented as settled until it is cleared, by checking it and either deleting the line or correcting the record.
- That a patient in the heart trial died on 2025-11-05 is from the trade press (CGTLive, 2025-11-09, citing the company); the cause given in January 2026 (an infection after a bowel perforation, not liver failure) is the chief executive's account at an investor conference as reported by Clinical Trials Arena on 2026-01-15. The company's own written statement of the cause and the registry's note of it were not found.